An X-ray diagnostic apparatus including a photon-counting detector can provide a high-contrast image of particular tissue (target substance) by creating count data based on a detection signal output from the photon-counting detector and performing a variety of image processing on the created count data.
In such an X-ray diagnostic apparatus, for example, photon count data indicating the number of photons in each of a plurality of energy bins of a particular kind is created based on a detection signal output from the photon-counting detector. A particular target substance that can be identified by the energy bins of the particular kind thus can be estimated with high precision. It is, however, difficult to estimate other target substances with high precision.
In an X-ray diagnostic apparatus, reduction in an exposure dose to a subject is also desired.